Field of the Invention
This application offers a new type of storage tank. The storage tank is a steel plate and concrete composite structure (tank unit and tank group) used for storing industrial liquid products below the sea waterline, such as crude oil, refined oil, LNG (liquefied natural gas), LPG (liquefied petroleum gas), and so on. In addition, the composite tank group would be used as a foundation to support offshore storage, drilling and production facilities.
Background of the Invention
As well known, the compressive strength of a concrete structure is much greater than the tensile strength. As a result, concrete tank is suitable to be external pressured rather than internal pressured. Currently, concrete construction technologies being used for internal pressure tanks are mainly: prestressed concrete structure and double steel-plate concrete structure (BI-STEEL). Based on theories, the two existing schemes for concrete internal pressure tanks are mature technologies. However, in order to resist the tensile stress in the tank wall caused by the internal pressure, a lot of special techniques are required. This causes plenty of challenges on the design and construction of concrete tanks and significantly increases the difficulty and complexity in construction work, construction period and cost.